Test stations are used by developers and manufacturers of fuel cell systems to test new designs and materials and to monitor product life cycles. Such test stations include numerous subsystems, such as gas mixing modules, humidification units, water management systems, load banks, measuring devices and system controllers. Test stations control the physical characteristics of the reactants and cooling fluid entering a fuel cell, to simulate the various conditions that a fuel cell would encounter during real world operation. Typically, all fuel cells require three material inputs to operate: a fuel, an oxidant and a cooling fluid. The fuel (typically hydrogen) and oxidant (typically air) are delivered to the fuel cell in the form of heated, and humidified gas. The gas temperature, pressure, flow rate and humidity are all controlled from the test station. The coolant (typically de-ionized water) is delivered to the fuel cell for thermal control. Controllable properties of the coolant include temperature, pressure, flow rate, and conductivity.
With the delivery of the following inputs, a fuel cell produces an electric potential across its terminals, from which current can be drawn. The test stations apply varying electrical loads, and measure the subsequent fuel cell voltage. Test stations may also include integrated data acquisition and reporting hardware and software for analyzing test results.
The data generated by test stations is relied upon by product development engineers to test assumptions and hypotheses, and to assist in making product design decisions. Accordingly, if the data generated by a test station is faulty, this may result in flawed design or production decisions having potentially serious and expensive consequences. It is therefore imperative that test station data be as accurate and reliable as possible.
Many fuel cell developers and manufacturers employ multiple fuel cell test stations located at different locations on site. Often such test stations are manufactured by different suppliers and comprise different combinations of testing equipment. However, despite their design differences, fuel cell test stations generally control and measure many of the same properties. Problems can arise if a product designer suspects that some of the test stations are not producing accurate and consistent results (and hence the data generated by different stations is not readily comparable). Prior to the present invention there was no way to verify that the instrumentation of each test station was calibrated to the same standard and hence it was difficult to compare and characterize fuel cell stacks tested at different stations. Previously, data output verification could only be performed on one type of device measuring one physical characteristic on one station. For example, if an operator suspected that a flow meter was faulty, it would be necessary to physically remove the flow meter from the test station and conduct bench tests to verify its accuracy. Alternatively, diverter valves would be required to isolate the instrument from the rest of the test station. In either case instrument verification and re-calibration was a painstaking and time consuming exercise.
The present invention has been developed to provide an integrated testing apparatus for quickly verifying the accuracy of data outputted by fuel cell test stations. Additionally, the invention can be used to simulate the behavior of an actual fuel cell allowing for the development of fuel cell tests. This avoids risking a valuable fuel cell during test development. The apparatus is portable so that it may be conveniently transported between the different test station locations.